Many fields of industry depend on manipulating and interpreting large sets of data. These include the obvious fields of statistics, genetics, engineering, science, astronomy, and the like, but also include perhaps less evident fields such as marketing, news media, telecommunications, medicine, finance, and library science. A common use of such data is for research and analysis.
Traditional systems used to interpret such data rely on representing the data to the user of the system in a format that conveys and enhances the understanding of the information in an effective manner, and permits the system user to quickly and efficiently specify and locate information of particular interest. A familiar presentation form for the presentation of structured information is that of an image of a table, also referred to herein as a “table image”, the particular details of which are disclosed in detail in U.S. Pat. Nos. 5,632,009, 5,880,742, 5,883,635 and 6,085,202, hereinafter referred to collectively as “Rao & Card”, and disclosed herein by reference. As used in the context of this application a “table” is an orderly, rectilinear arrangement of information, ordered in a rectangular form of rows and columns and having identifiers, such as labels, arranged at the periphery of the table. The intersection of a row and column in a table defines a data location, typically called a “cell”, and may include alphabetic and numeric character data or arithmetic operators or formulas. A popular application of a table image is the “spreadsheet” presentation format used by spreadsheet applications to present a tabular image of underlying data stored in the memory of a system.
In the context of this invention a “data image” is a larger set of data information, which may include tables, but may also include such display mechanisms as scatter plots and contour plots. Locations in data images can be defined by the intersection of “coordinates” in two or more dimensional axes.
While most research and analysis can be classified as direct, or targeted to a specific investigation, a large portion of such research is serendipitous in nature, and includes the stereotypical image of the scientist poring over large volumes of data, trying to ascertain perhaps that best combination of results, or those results which are dependent on, or effect, other measurements outside the immediate scope of the data. The ever-increasing importance of computer techniques has usurped that image of the scientist poring over a set of books with one of a scientist poring over a computer screen, upon which graphical representations of the data are shown. The common format of this representation are lists, tables, graphs, scatter plots, etc., which share a common attribute in that they are all somewhat “dumb”, and don't provide much to the viewer beyond that which a paper printout would provide. As such the traditional methods of computerized data representation and visualization are sorely lacking in the degree to which they make the most of modern computer processing power.
One problem common with the presentation of data in a table image format of any size involves the display of character, or non-graphical, display features such as text and numbers, in the table or image cells or regions representing the data in the information structure. Rows and columns of text and numbers do not necessarily present the information in the data structure in a form meaningful for detecting patterns in the information, or for seeing overall trends in the data. Another problem specifically involves the presentation of large table images representing a large information structure when there is too much data for all of the data to be clearly presented in a table image that fits in the display area of the system display device. To address this problem, some application programs present only a portion of the table image in the display area, and provide a function for the system user to scroll through the table image to reach portions not currently visible in the display area in order to access the data represented by the character images in the table cells. As scrolling brings new cells of the table image into view in the display area, the previously displayed cells, including row and column identifiers such as labels, typically disappear from the display area, and global context information, important for navigating around the table image and for understanding the data that is currently displayed, is lost from the systems user's view. This presentation technique of scrolling through a large table image is sometimes referred to as a “time strategy” for presenting information, in that the user controls the display of sequential multiple views of the data over a period of time in order to view all of the data.
A number of other information presentation techniques are useful for presentation of data information on visual displays. One such technique is the “space strategy”, which uses layout and graphic design techniques to present substantially all the information in a particular data structure within one view in the workspace or working windows. The space strategy typically involves the presentation of information in a primarily graphical or pictorial form rather than in non-graphical or character or textual form because of the size limitations of the work space of a given display device, and because of limitations on the amount of detail that a user is actually able to perceive within a particular area of the workspace.
Another design strategy involves the presentation of specific information of particular interest to a system user while concurrently maintaining and displaying the global context and structure of the body of information from which the specific information was selected, thus providing a balance of local detail and global context. Local detail is needed for local interactions with, or local investigation of, the data, while the global context is needed to tell the user what other parts of the data exist and where they are located in the workspace. One common implementation of this strategy presents the global information in less detail than the local information. This strategy may be considered a combination of the time and space strategies discussed above.
Both the time and space strategies or techniques are especially important when the data to be presented is part of a large information structure, such as a computer program, a database, a large collection of documents, etc., but they are also useful for the presentation of information structures of virtually any size. The subsequent discussion of the application of these strategies in the invention described herein as applied to such large information structures is not intended to necessarily limit the invention's application to large data structures.
Some attempts have been made to augment the traditional computerized or computer-based data visualization process using such design strategies. Foremost among these attempts are the various table-oriented visualization tools, such as the Table Lens product from Xerox, Inc., which acts as an intelligent magnifying glass or window that can be moved around a table of data, or a spreadsheet, by a human operator or user. As the window is moved over a section of data or a number of data cells, the underlying source data is parsed for references to additional data that is referenced or related to the visible data cells on the screen. This additional data is used to modify the window, perhaps adding color, or displaying the actual additional data, for those cells contained within the window or workspace. FIG. 1 shows an example of a focus+context matrix as it might be applied to a spreadsheet. In this example, a central focus region denoted by the matrix of rows 4–6 and columns G-I is created so as to “drill-down” or interrogate the related underlying data. The method can for example be used to provide a focus+context view into a table as further illustrated in the Table Lens illustrated in FIG. 2. As shown in FIG. 2, the Table Lens can be used to provide a detailed view into the data supporting the graphical view appearance of the table shown therein. The details of these and other related systems are described in detail in Rao & Card, which describes primarily the Table Lens technologies.